Maker

Hilger & Watts Ltd, London

Model

---

Serial Number

n/a

Dimensions

40 x 30 x 70 mm

Image

Description

This double pentaprism (optical square) is neither round nor rectangular in plan view. The upper window diverts the view to the left, the lower window to the right. There are no windows for the view straight ahead.

The housing and handle are black and made from hard plastic (possibly Bakelite). The handle is hollow and 38 mm long and has an outer diameter of 12 mm.

The top surface shows "HILGER & WATSS Ltd" in raised letters and the "W WATTS LONDON" symbol (also raised ratherthan engraved).

Made in England is noted at the top of the handle. Two screws are used to hold the upper andlower parts of the device together.

History & comments

Conservation

in small leather pouch 43 mm diameter, 85 mm long.

Condition

excellent

Remarks

"16" marked in white paint on top surface (for bookkeeping during student exercises)

Dates

Catalogued and photographed by JMR on 8 July 2015.